Linking Children with Parent

Hello Community,

Here is the Source Data where I'm currently stuck at,

So the idea is that the Number column represents the Parent, and the Expense Items.Number represents the children. So the data is messed, we cannot tie back one to one. 

First Issue - Linking Children with Respective Parent.
The Name column can be used as an identifier as for the children, In the Name column it will be duplicated accordingly, but in the Number column, we can see that it has blanks. I already have a combined Name column called Expense Name which combines the Name and Expense Items.Name. So for now, I just want the children to be right below the parents, as i want the visualization in dashboard to be - Number, Expense Items.Number, Expense Name and etc. Please see the copied power query table in the excel sheet at the top, "Source Data". Thank you all.

Second Issue - Sorting the Data

As you can see, the Data is not in a proper sequence because the Number is different but can still be seen which one comes first, So is there any way to address this? Please skip if no. I'll use the usual create new column and sort by the column. Thank you